Unfortunately, this point of view has little merit.
Security is all or nothing. You can't have a little bit of this and a little bit of that. Unless the parts of the web browser that can be "influenced" by external attacker (directly or indirectly) are written 100% in a memory safe language, you simply have no real security but the illusion of such.
And this is how that hypothetical browser fails, and why it will never amount to anything re: security, since it's gonna end up using a gazillion of C libraries, all of them full of bugs and possibly vulnerable to security exploits.
One could say that Rust also fails by allowing "unsafe" code in its core design but it's still too early to see how that will play out.
Security is not all or nothing. You can definitely say that X is more secure than Y even if both have bugs, so long as X's bugs are less critical and less frequent.
As an example, I would happily claim that nginx is more secure than wordpress or the average php website written with mysql_query in the 90s. Does nginx have bugs? Probably somewhere in there. Are they as likely to be found, exploited, or (when exploited) lead to as serious issues? I doubt it.
Security is often about many many levels. A good example of this is Chrome, its sandboxing, operating system memory randomization, and user privileges. When someone finds a bug in v8, to turn it into root on the box requires bugs in all those layers (see writeups for pwn2own).
Generally, an improvement in security at any layer will reduce the impact of bugs at other layers. I'd absolutely rather have a browser written 20% in rust than 0% in rust.
Security is all or nothing. You can't have a little bit of this and a little bit of that. Unless the parts of the web browser that can be "influenced" by external attacker (directly or indirectly) are written 100% in a memory safe language, you simply have no real security but the illusion of such.
And this is how that hypothetical browser fails, and why it will never amount to anything re: security, since it's gonna end up using a gazillion of C libraries, all of them full of bugs and possibly vulnerable to security exploits.
One could say that Rust also fails by allowing "unsafe" code in its core design but it's still too early to see how that will play out.